Delays in the postnatal increase of cerebral cytochrome concentrations in lead-exposed rats

Bull, Richard J.; Lutkenhoff, S.D.; McCarty, Garland E.; Miller, Ronald G.

doi:10.1016/0028-3908(79)90013-3

Cited by 42 publications

(7 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When [2,3-'4C]succinate and [ 1,4-'4C]succinate were compared as precursors of 5-aminolaevulinate, a 15-40% greater incorporation of the methylene carbon atoms of succinate was found with both liver and brain (Table 1), compared with the incorporation of the carboxy carbon atoms of succinate. Postnatal development of S-aminolaevulinate synthase in brain and liver Previous work has shown an age-dependent maturation of several metabolic pathways in the brain, including the respiratory activity of brain (Land et al, 1977) and its concentration of mitochondrial cytochromes (Chepelinsky & Arnaiz, 1970;Bull et al, 1979). All of these components or activities are very low at birth, then steadily increase reaching the adult activity at approx.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Brain 5-aminolaevulinate synthase Developmental aspects and evidence for regulatory role

Matteis¹,

Zetterlund²,

Wetterberg³

1981

Biochemical Journal

View full text Add to dashboard Cite

1. Brain 5-aminolaevulinate synthase showed a peak of increased activity in the first few weeks of life, which preceded and accompanied the development of brain cytochromes. 2. In the brain of the adult rat the activity of the enzyme was only 20% of that in the liver (on a per g wet wt. basis), but it was still probably sufficient to maintain the turnover of brain cytochromes. 3. The brain synthase activity could be decreased by treatment of rats with cycloheximide or with large doses of 5-aminolaevulinate, especially when this precursor was given as the methyl ester. 4. Injected haematin and CoCl2 markedly inhibited the synthase activity in the liver but failed to affect the brain enzyme; neither was taken up by the brain in vivo. 5. It is concluded that the brain can itself produce the haem required for the synthesis and turnover of its own haemoproteins and that 5-aminolaevulinate synthase may regulate the pathway in brain as in other tissues. 6. The relevance of the present findings to the pathogenesis of the neurological symptoms of acute porphyria and to the beneficial effect of exogenous haematin in porphyric patients is briefly considered.

show abstract

Section: Resultsmentioning

confidence: 99%

“…In the adult rat both the concentration of the main haemoproteins of the brain (the mitochondrial cytochromes; see Bull et al, 1979) and the activity of brain 5-aminolaevulinate synthase (Fig. la) are approximately in a steady state.…”

Section: Discussionmentioning

confidence: 99%

Brain 5-aminolaevulinate synthase Developmental aspects and evidence for regulatory role

Matteis¹,

Zetterlund²,

Wetterberg³

1981

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…The amount of haem and therefore of 5aminolaevulinate required to maintain the turnover of the cerebellar cytochromes was calculated using the t,,, value (125 h) obtained in this work for the slow phase of liver haem turnover and assuming the total cytochrome content (46.8 nmoVg wet weight) given by Bull et al (1979) for cortical slices. The amount of 5-aminolaevulinate required (35 pmoY midg of cerebellum) is compatible with the activity of 5-aminolaevulinate synthase observed in this work (37-53 pmollmidg, Table 3).…”

Section: Inhibition Of Cerebellar Haem Biosynthesis Caused By Succinymentioning

confidence: 99%

Studies on Cerebellar Haem Metabolism in the Rat In Vivo

Matters

Ray

1982

Journal of Neurochemistry

View full text Add to dashboard Cite

Rats were injected intraventricularly with 5-amino[4-14C]laevulinate and the radioactivity recovered in the total cerebellum homogenate and in its haem and porphyrin fractions was determined in time. Two phases could be distinguished in the decline of haem radioactivity, suggesting labelling of at least two pools of widely different turnover rates. Succinyl acetone, when injected intraventricularly, caused a marked and long-lasting inhibition of cerebellar 5-aminolaevulinate dehydratase activity and a corresponding inhibition of the incorporation of [14C]5-aminolaevulinate into cerebellar haem in vivo. Inhibition of cerebellar haem biosynthesis by succinylacetone was followed by stimulation of the first enzyme of the pathway, 5-aminolaevulinate synthase, whereas intraventricular injection of haematin led to a significant depression of the activity of the enzyme. This suggested that the cerebellar 5-aminolaevulinate synthetase is regulated by haem through a negative feedback mechanism. Rats given repeated doses of succinylacetone, so as to maintain 80% inhibition of their cerebellar 5-aminolaevulinate dehydratase activity for 5 days, failed to exhibit any obvious symptoms of toxicity but became more sensitive to the neurotoxic effects of large intraventricular doses of 5-aminolaevulinate.

show abstract

“…Increasing duration of exposure to lead was associated with decreasing microsomal P-450 content and decreasing microsomal heme content ). In addition, delays in the synthesis of the respiratory chain hemoprotein cytochrome C have been noted during administration of lead to neonatal rats (Bull et al 1979). …”

Section: Health Effects 1986a) Formation Of the Heme-containing Cytomentioning

confidence: 99%

Characterizing Golden Eagle Risk to Lead and Anticoagulant Rodenticide Exposure: A Review

Herring

Eagles‐Smith

Buck

2017

Journal of Raptor Research

View full text Add to dashboard Cite

Delays in the postnatal increase of cerebral cytochrome concentrations in lead-exposed rats

Cited by 42 publications

References 23 publications

Brain 5-aminolaevulinate synthase Developmental aspects and evidence for regulatory role

Brain 5-aminolaevulinate synthase Developmental aspects and evidence for regulatory role

Studies on Cerebellar Haem Metabolism in the Rat In Vivo

Characterizing Golden Eagle Risk to Lead and Anticoagulant Rodenticide Exposure: A Review

Contact Info

Product

Resources

About